Queen's men

From A Wiki of Ice and Fire

Historically, Queen Selyse Florent was among the first in Dragonstone to convert, and it was initially by her insistence that Stannis took notice of the red priestess, Melisandre. Calling them the "queen's" men alludes to the fact that Selyse is a vocal supporter of Melisandre and of her god, arguably more so than Stannis himself, and helps in telling them apart from the so-called king's men who are also supporters of Stannis's cause yet have kept the Faith of the Seven.[1] However, an alternate interpretation is that the queen they are loyal to is not Selyse but rather Melisandre, who is in many senses closer to Stannis than Selyse.[2]

They often have a fiery heart, the emblem of the Lord of Light, embroidered on their breasts signifying their allegiance.[3]